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| Mirrors > Home > ILE Home > Th. List > freq2 | GIF version | ||
| Description: Equality theorem for the well-founded predicate. (Contributed by NM, 3-Apr-1994.) | 
| Ref | Expression | 
|---|---|
| freq2 | ⊢ (𝐴 = 𝐵 → (𝑅 Fr 𝐴 ↔ 𝑅 Fr 𝐵)) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | frforeq2 4380 | . . 3 ⊢ (𝐴 = 𝐵 → ( FrFor 𝑅𝐴𝑠 ↔ FrFor 𝑅𝐵𝑠)) | |
| 2 | 1 | albidv 1838 | . 2 ⊢ (𝐴 = 𝐵 → (∀𝑠 FrFor 𝑅𝐴𝑠 ↔ ∀𝑠 FrFor 𝑅𝐵𝑠)) | 
| 3 | df-frind 4367 | . 2 ⊢ (𝑅 Fr 𝐴 ↔ ∀𝑠 FrFor 𝑅𝐴𝑠) | |
| 4 | df-frind 4367 | . 2 ⊢ (𝑅 Fr 𝐵 ↔ ∀𝑠 FrFor 𝑅𝐵𝑠) | |
| 5 | 2, 3, 4 | 3bitr4g 223 | 1 ⊢ (𝐴 = 𝐵 → (𝑅 Fr 𝐴 ↔ 𝑅 Fr 𝐵)) | 
| Colors of variables: wff set class | 
| Syntax hints: → wi 4 ↔ wb 105 ∀wal 1362 = wceq 1364 FrFor wfrfor 4362 Fr wfr 4363 | 
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-ia1 106 ax-ia2 107 ax-ia3 108 ax-io 710 ax-5 1461 ax-7 1462 ax-gen 1463 ax-ie1 1507 ax-ie2 1508 ax-8 1518 ax-10 1519 ax-11 1520 ax-i12 1521 ax-bndl 1523 ax-4 1524 ax-17 1540 ax-i9 1544 ax-ial 1548 ax-i5r 1549 ax-ext 2178 | 
| This theorem depends on definitions: df-bi 117 df-tru 1367 df-nf 1475 df-sb 1777 df-clab 2183 df-cleq 2189 df-clel 2192 df-nfc 2328 df-ral 2480 df-in 3163 df-ss 3170 df-frfor 4366 df-frind 4367 | 
| This theorem is referenced by: weeq2 4392 | 
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